1. Field of the Invention
The present invention relates to computational circuits for calculating addition, multiplication, comparison, quantizing and exponentials of substantially analog values.
2. Description of the Related Art
In conventional digital computers, computations are performed by using many combinations of simple digital logic circuits. Digital computation is accurate and redundant. However, it is limited due to the large equipment costs necessary for high precision manufacturing of digital circuits. Analog computation was frequently used for solving differential equations, but because of the limitations of digital devices noted above, analog computation is now attracting attention. Operational amplifiers are used in conventional analog computation. However, a lot of electric power is necessary for large scale analog computation because it is driven by current. As a result, it is difficult to provide a practical circuit for a large scale complicated calculation.